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 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package javax.swing;

import javax.swing.plaf.*;
import javax.accessibility.*;

import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;


/**
 * <code>JSeparator</code> provides a general purpose component for
 * implementing divider lines - most commonly used as a divider
 * between menu items that breaks them up into logical groupings.
 * Instead of using <code>JSeparator</code> directly,
 * you can use the <code>JMenu</code> or <code>JPopupMenu</code>
 * <code>addSeparator</code> method to create and add a separator.
 * <code>JSeparator</code>s may also be used elsewhere in a GUI
 * wherever a visual divider is useful.
 *
 * <p>
 *
 * For more information and examples see
 * <a
 * href="https://docs.oracle.com/javase/tutorial/uiswing/components/menu.html">How to Use Menus</a>,
 * a section in <em>The Java Tutorial.</em>
 * <p>
 * <strong>Warning:</strong> Swing is not thread safe. For more
 * information see <a
 * href="package-summary.html#threading">Swing's Threading
 * Policy</a>.
 * <p>
 * <strong>Warning:</strong>
 * Serialized objects of this class will not be compatible with
 * future Swing releases. The current serialization support is
 * appropriate for short term storage or RMI between applications running
 * the same version of Swing.  As of 1.4, support for long term storage
 * of all JavaBeans&trade;
 * has been added to the <code>java.beans</code> package.
 * Please see {@link java.beans.XMLEncoder}.
 *
 * @author Georges Saab
 * @author Jeff Shapiro
 * @beaninfo attribute: isContainer false description: A divider between menu items.
 */
@SuppressWarnings("serial")
public class JSeparator extends JComponent implements SwingConstants, Accessible {

  /**
   * @see #getUIClassID
   * @see #readObject
   */
  private static final String uiClassID = "SeparatorUI";

  private int orientation = HORIZONTAL;

  /**
   * Creates a new horizontal separator.
   */
  public JSeparator() {
    this(HORIZONTAL);
  }

  /**
   * Creates a new separator with the specified horizontal or
   * vertical orientation.
   *
   * @param orientation an integer specifying <code>SwingConstants.HORIZONTAL</code> or
   * <code>SwingConstants.VERTICAL</code>
   * @throws IllegalArgumentException if <code>orientation</code> is neither
   * <code>SwingConstants.HORIZONTAL</code> nor <code>SwingConstants.VERTICAL</code>
   */
  public JSeparator(int orientation) {
    checkOrientation(orientation);
    this.orientation = orientation;
    setFocusable(false);
    updateUI();
  }

  /**
   * Returns the L&amp;F object that renders this component.
   *
   * @return the SeparatorUI object that renders this component
   */
  public SeparatorUI getUI() {
    return (SeparatorUI) ui;
  }

  /**
   * Sets the L&amp;F object that renders this component.
   *
   * @param ui the SeparatorUI L&amp;F object
   * @beaninfo bound: true hidden: true attribute: visualUpdate true description: The UI object that
   * implements the Component's LookAndFeel.
   * @see UIDefaults#getUI
   */
  public void setUI(SeparatorUI ui) {
    super.setUI(ui);
  }

  /**
   * Resets the UI property to a value from the current look and feel.
   *
   * @see JComponent#updateUI
   */
  public void updateUI() {
    setUI((SeparatorUI) UIManager.getUI(this));
  }


  /**
   * Returns the name of the L&amp;F class that renders this component.
   *
   * @return the string "SeparatorUI"
   * @see JComponent#getUIClassID
   * @see UIDefaults#getUI
   */
  public String getUIClassID() {
    return uiClassID;
  }


  /**
   * See <code>readObject</code> and <code>writeObject</code> in
   * <code>JComponent</code> for more
   * information about serialization in Swing.
   */
  private void writeObject(ObjectOutputStream s) throws IOException {
    s.defaultWriteObject();
    if (getUIClassID().equals(uiClassID)) {
      byte count = JComponent.getWriteObjCounter(this);
      JComponent.setWriteObjCounter(this, --count);
      if (count == 0 && ui != null) {
        ui.installUI(this);
      }
    }
  }

  /**
   * Returns the orientation of this separator.
   *
   * @return The value of the orientation property, one of the following constants defined in
   * <code>SwingConstants</code>: <code>VERTICAL</code>, or <code>HORIZONTAL</code>.
   * @see SwingConstants
   * @see #setOrientation
   */
  public int getOrientation() {
    return this.orientation;
  }

  /**
   * Sets the orientation of the separator.
   * The default value of this property is HORIZONTAL.
   *
   * @param orientation either <code>SwingConstants.HORIZONTAL</code> or
   * <code>SwingConstants.VERTICAL</code>
   * @throws IllegalArgumentException if <code>orientation</code> is neither
   * <code>SwingConstants.HORIZONTAL</code> nor <code>SwingConstants.VERTICAL</code>
   * @beaninfo bound: true preferred: true enum: HORIZONTAL SwingConstants.HORIZONTAL VERTICAL
   * SwingConstants.VERTICAL attribute: visualUpdate true description: The orientation of the
   * separator.
   * @see SwingConstants
   * @see #getOrientation
   */
  public void setOrientation(int orientation) {
    if (this.orientation == orientation) {
      return;
    }
    int oldValue = this.orientation;
    checkOrientation(orientation);
    this.orientation = orientation;
    firePropertyChange("orientation", oldValue, orientation);
    revalidate();
    repaint();
  }

  private void checkOrientation(int orientation) {
    switch (orientation) {
      case VERTICAL:
      case HORIZONTAL:
        break;
      default:
        throw new IllegalArgumentException("orientation must be one of: VERTICAL, HORIZONTAL");
    }
  }


  /**
   * Returns a string representation of this <code>JSeparator</code>.
   * This method
   * is intended to be used only for debugging purposes, and the
   * content and format of the returned string may vary between
   * implementations. The returned string may be empty but may not
   * be <code>null</code>.
   *
   * @return a string representation of this <code>JSeparator</code>
   */
  protected String paramString() {
    String orientationString = (orientation == HORIZONTAL ?
        "HORIZONTAL" : "VERTICAL");

    return super.paramString() +
        ",orientation=" + orientationString;
  }

/////////////////
// Accessibility support
////////////////

  /**
   * Gets the AccessibleContext associated with this JSeparator.
   * For separators, the AccessibleContext takes the form of an
   * AccessibleJSeparator.
   * A new AccessibleJSeparator instance is created if necessary.
   *
   * @return an AccessibleJSeparator that serves as the AccessibleContext of this JSeparator
   */
  public AccessibleContext getAccessibleContext() {
    if (accessibleContext == null) {
      accessibleContext = new AccessibleJSeparator();
    }
    return accessibleContext;
  }

  /**
   * This class implements accessibility support for the
   * <code>JSeparator</code> class.  It provides an implementation of the
   * Java Accessibility API appropriate to separator user-interface elements.
   * <p>
   * <strong>Warning:</strong>
   * Serialized objects of this class will not be compatible with
   * future Swing releases. The current serialization support is
   * appropriate for short term storage or RMI between applications running
   * the same version of Swing.  As of 1.4, support for long term storage
   * of all JavaBeans&trade;
   * has been added to the <code>java.beans</code> package.
   * Please see {@link java.beans.XMLEncoder}.
   */
  @SuppressWarnings("serial")
  protected class AccessibleJSeparator extends AccessibleJComponent {

    /**
     * Get the role of this object.
     *
     * @return an instance of AccessibleRole describing the role of the object
     */
    public AccessibleRole getAccessibleRole() {
      return AccessibleRole.SEPARATOR;
    }
  }
}
